============== SAM4S Xplained ============== This README discusses issues unique to NuttX configurations for the Atmel SAM4S Xplained development board. This board features the ATSAM4S16C MCU with 1MB FLASH and 128KB. The SAM4S Xplained features: * 120 MHz Cortex-M4 with MPU * 12MHz crystal (no 32.768KHz crystal) * Segger J-Link JTAG emulator on-board for program and debug * MICRO USB A/B connector for USB connectivity * IS66WV51216DBLL ISSI SRAM 8Mb 512K x 16 55ns PSRAM 2.5v-3.6v * Four Atmel QTouch buttons * External voltage input * Four LEDs, two controllable from software * Xplained expansion headers * Footprint for external serial Flash (not fitted) PIO Muliplexing =============== ==== ======================== PIN FUNCTION ==== ======================== PA0 SMC_A17 PA1 SMC_A18 PA2 J3.7 default PA3 J1.1 & J4.1 PA4 J1.2 & J4.2 PA5 User_button BP2 PA6 J3.7 optional PA7 CLK_32K PA8 CLK_32K PA9 RX_UART0 PA10 TX_UART0 PA11 J3.2 default PA12 MISO PA13 MOSI PA14 SPCK PA15 J3.5 PA16 J3.6 PA17 J2.5 PA18 J3.4 & SMC_A14 PA19 J3.4 optional & SMC_A15 PA20 J3.1 & SMC_A16 PA21 J2.6 PA22 J2.1 PA23 J3.3 PA24 TSLIDR_SL_SN PA25 TSLIDR_SL_SNSK PA26 TSLIDR_SM_SNS PA27 TSLIDR_SM_SNSK PA28 TSLIDR_SR_SNS PA29 TSLIDR_SR_SNSK PA30 J4.5 PA31 J1.5 PB0 J2.3 default PB1 J2.4 PB2 J1.3 & J4.3 PB3 J1.4 & J4.4 PB4 JTAG PB5 JTAG PB6 JTAG PB7 JTAG PB8 CLK_12M PB9 CLK_12M PB10 USB_DDM PB11 USB_DDP PB12 ERASE PB13 J2.3 optional PB14 N/A PC0 SMC_D0 PC1 SMC_D1 PC2 SMC_D2 PC3 SMC_D3 PC4 SMC_D4 PC5 SMC_D5 PC6 SMC_D6 PC7 SMC_D7 PC8 SMC_NWE PC9 Power on detect PC10 User LED D9 PC11 SMC_NRD PC12 J2.2 PC13 J2.7 PC14 SMC_NCS0 PC15 SMC_NSC1 PC16 N/A PC17 User LED D10 PC18 SMC_A0 PC19 SMC_A1 PC20 SMC_A2 PC21 SMC_A3 PC22 SMC_A4 PC23 SMC_A5 PC24 SMC_A6 PC25 SMC_A7 PC26 SMC_A8 PC27 SMC_A9 PC28 SMC_A10 PC29 SMC_A11 PC30 SMC_A12 PC31 SMC_A13 ==== ======================== Buttons and LEDs ================ Buttons ------- The SAM4S Xplained has two mechanical buttons. One button is the RESET button connected to the SAM4S reset line and the other is a generic user configurable button labeled BP2 and connected to GPIO PA5. When a button is pressed it will drive the I/O line to GND. LEDs ---- There are four LEDs on board the SAM4X Xplained board, two of these can be controlled by software in the SAM4S: ================ ===== LED GPIO ================ ===== D9 Yellow LED PC10 D10 Yellow LED PC17 ================ ===== Both can be illuminated by driving the GPIO output to ground (low). These LEDs are not used by the board port unless ``CONFIG_ARCH_LEDS`` is defined. In that case, the usage by the board port is defined in ``include/board.h`` and ``src/sam_leds.c``. The LEDs are used to encode OS-related events as follows: =================== ======================= ======== ======== SYMBOL Meaning D9 D10 =================== ======================= ======== ======== LED_STARTED NuttX has been started OFF OFF LED_HEAPALLOCATE Heap has been allocated OFF OFF LED_IRQSENABLED Interrupts enabled OFF OFF LED_STACKCREATED Idle stack created ON OFF LED_INIRQ In an interrupt N/C N/C LED_SIGNAL In a signal handler N/C N/C LED_ASSERTION An assertion failed N/C N/C LED_PANIC The system has crashed OFF Blinking LED_IDLE MCU is is sleep mode N/A N/A =================== ======================= ======== ======== Thus if D9 is statically on, NuttX has successfully booted and is, apparently, running normmally. If D10 is flashing at approximately 2Hz, then a fatal error has been detected and the system has halted. Serial Consoles =============== UART1 ----- If you have a TTL to RS-232 converter then this is the most convenient serial console to use. UART1 is the default in all of these configurations. ================ ========= ========= SIGNAL CONNECTOR CONNECTOR ================ ========= ========= UART1 RXD PB2 J1 pin 3 J4 pin 3 UART1 TXD PB3 J1 pin 4 J4 pin 4 GND J1 pin 9 J4 pin 9 Vdd J1 pin 10 J4 pin 10 ================ ========= ========= USART1 ------ USART1 is another option: ================ ========= SIGNAL CONNECTOR ================ ========= USART1 RXD PA21 J2 pin 6 USART1 TXD PA22 J2 pin 1 GND J2 pin 9 Vdd J2 pin 10 ================ ========= Virtual COM Port ---------------- Yet another option is to use UART0 and the virtual COM port. This option may be more convenient for long term development, but was painful to use during board bring-up. The SAM4S Xplained contains an Embedded Debugger (EDBG) that can be used to program and debug the ATSAM4S16C using Serial Wire Debug (SWD). The Embedded debugger also include a Virtual Com port interface over USART1. Virtual COM port connections: ============== ============== AT91SAM4S16 ATSAM3U4CAU ============== ============== PA9 RX_UART0 PA9_4S PA12 PA10 TX_UART0 RX_3U PA11 ============== ============== SAM4S Xplained-specific Configuration Options ============================================= * ``CONFIG_ARCH``: Identifies the ``arch/`` subdirectory. This should be set to: * ``CONFIG_ARCH=arm`` * ``CONFIG_ARCH_family``: For use in C code: * ``CONFIG_ARCH_ARM=y`` * ``CONFIG_ARCH_architecture``: For use in C code: * ``CONFIG_ARCH_CORTEXM4=y`` * ``CONFIG_ARCH_CHIP``: Identifies the ``arch/*/chip`` subdirectory * ``CONFIG_ARCH_CHIP="sam34"`` * ``CONFIG_ARCH_CHIP_name``: For use in C code to identify the exact chip: ``CONFIG_ARCH_CHIP_SAM34`` ``CONFIG_ARCH_CHIP_SAM4S`` ``CONFIG_ARCH_CHIP_ATSAM4S16C`` * ``CONFIG_ARCH_BOARD``: Identifies the ``boards/`` subdirectory and hence, the board that supports the particular chip or SoC. * ``CONFIG_ARCH_BOARD=sam4s:xplained`` (for the SAM4S Xplained development board) * ``CONFIG_ARCH_BOARD_name``: For use in C code * ``CONFIG_ARCH_BOARD_SAM4S_XPLAINED=y`` * ``CONFIG_ARCH_LOOPSPERMSEC``: Must be calibrated for correct operation of delay loops * ``CONFIG_ENDIAN_BIG``: define if big endian (default is little endian) * ``CONFIG_RAM_SIZE``: Describes the installed DRAM (SRAM in this case): * ``CONFIG_RAM_SIZE=0x00008000`` (32Kb) * ``CONFIG_RAM_START``: The start address of installed DRAM * ``CONFIG_RAM_START=0x20000000`` * ``CONFIG_ARCH_LEDS``: Use LEDs to show state. Unique to boards that have LEDs * ``CONFIG_ARCH_INTERRUPTSTACK``: This architecture supports an interrupt stack. If defined, this symbol is the size of the interrupt stack in bytes. If not defined, the user task stacks will be used during interrupt handling. * ``CONFIG_ARCH_STACKDUMP``: Do stack dumps after assertions * ``CONFIG_ARCH_LEDS``: Use LEDs to show state. Unique to board architecture. Individual subsystems can be enabled: * ``CONFIG_SAM34_RTC``: Real Time Clock * ``CONFIG_SAM34_RTT``: Real Time Timer * ``CONFIG_SAM34_WDT``: Watchdog Timer * ``CONFIG_SAM34_UART0``: UART 0 * ``CONFIG_SAM34_UART1``: UART 1 * ``CONFIG_SAM34_SMC``: Static Memory Controller * ``CONFIG_SAM34_USART0``: USART 0 * ``CONFIG_SAM34_USART1``: USART 1 * ``CONFIG_SAM34_HSMCI``: High Speed Multimedia Card Interface * ``CONFIG_SAM34_TWI0``: Two-Wire Interface 0 * ``CONFIG_SAM34_TWI1``: Two-Wire Interface 1 * ``CONFIG_SAM34_SPI0``: Serial Peripheral Interface * ``CONFIG_SAM34_SSC``: Synchronous Serial Controller * ``CONFIG_SAM34_TC0``: Timer Counter 0 * ``CONFIG_SAM34_TC1``: Timer Counter 1 * ``CONFIG_SAM34_TC2``: Timer Counter 2 * ``CONFIG_SAM34_TC3``: Timer Counter 3 * ``CONFIG_SAM34_TC4``: Timer Counter 4 * ``CONFIG_SAM34_TC5``: Timer Counter 5 * ``CONFIG_SAM34_ADC12B``: 12-bit Analog To Digital Converter * ``CONFIG_SAM34_DACC``: Digital To Analog Converter * ``CONFIG_SAM34_PWM``: Pulse Width Modulation * ``CONFIG_SAM34_CRCCU``: CRC Calculation Unit * ``CONFIG_SAM34_ACC``: Analog Comparator * ``CONFIG_SAM34_UDP``: USB Device Port Some subsystems can be configured to operate in different ways. The drivers need to know how to configure the subsystem. * ``CONFIG_SAM34_GPIOA_IRQ`` * ``CONFIG_SAM34_GPIOB_IRQ`` * ``CONFIG_SAM34_GPIOC_IRQ`` * ``CONFIG_USART0_SERIALDRIVER`` * ``CONFIG_USART1_SERIALDRIVER`` * ``CONFIG_USART2_SERIALDRIVER`` * ``CONFIG_USART3_SERIALDRIVER`` ST91SAM4S specific device driver settings * ``CONFIG_U[S]ARTn_SERIAL_CONSOLE`` - selects the USARTn (n=0,1,2,3) or UART m (m=4,5) for the console and ttys0 (default is the USART1). * ``CONFIG_U[S]ARTn_RXBUFSIZE`` - Characters are buffered as received. This specific the size of the receive buffer * ``CONFIG_U[S]ARTn_TXBUFSIZE`` - Characters are buffered before being sent. This specific the size of the transmit buffer * ``CONFIG_U[S]ARTn_BAUD`` - The configure BAUD of the UART. Must be * ``CONFIG_U[S]ARTn_BITS`` - The number of bits. Must be either 7 or 8. * ``CONFIG_U[S]ARTn_PARTIY`` - 0=no parity, 1=odd parity, 2=even parity * ``CONFIG_U[S]ARTn_2STOP`` - Two stop bits Configurations ============== Each SAM4S Xplained configuration is maintained in a sub-directory and can be selected as follow: .. code:: console $ tools/configure.shsam4s-xplained: Before building, make sure the ``PATH`` environment variable includes the correct path to the directory than holds your toolchain binaries. And then build NuttX by simply typing the following. At the conclusion of the make, the nuttx binary will reside in an ELF file called, simply, nuttx. .. code:: console $ make The ```` that is provided above as an argument to the ``tools/configure.sh`` must be is one of the following. 1. These configurations use the mconf-based configuration tool. To change any of these configurations using that tool, you should: a. Build and install the ``kconfig-mconf`` tool. See ``nuttx/README.txt`` see additional README.txt files in the NuttX tools repository. b. Execute 'make menuconfig' in nuttx/ in order to start the reconfiguration process. 2. Unless stated otherwise, all configurations generate console output on UART1 which is available on J1 or J4 (see the section "Serial Consoles" above). USART1 or the virtual COM port on UART0 are options. The virtual COM port could be used, for example, by reconfiguring to use UART0 like: System Type -> AT91SAM3/4 Peripheral Support * ``CONFIG_SAM_UART0=y`` * ``CONFIG_SAM_UART1=n`` Device Drivers -> Serial Driver Support -> Serial Console * ``CONFIG_UART0_SERIAL_CONSOLE=y`` Device Drivers -> Serial Driver Support -> UART0 Configuration * ``CONFIG_UART0_2STOP=0`` * ``CONFIG_UART0_BAUD=115200`` * ``CONFIG_UART0_BITS=8`` * ``CONFIG_UART0_PARITY=0`` * ``CONFIG_UART0_RXBUFSIZE=256`` * ``CONFIG_UART0_TXBUFSIZE=256`` 3. Unless otherwise stated, the configurations are setup for Linux (or any other POSIX environment like Cygwin under Windows): Build Setup: * ``CONFIG_HOST_LINUX=y``: Linux or other POSIX environment 4. These configurations use the older, OABI, buildroot toolchain. But that is easily reconfigured: System Type -> Toolchain: * ``CONFIG_ARM_TOOLCHAIN_BUILDROOT=y``: Buildroot toolchain * ``CONFIG_ARM_TOOLCHAIN_BUILDROOT_OABI=y``: Older, OABI toolchain If you want to use the Atmel GCC toolchain, here are the steps to do so: Build Setup: * ``CONFIG_HOST_WINDOWS=y``: Windows * ``CONFIG_HOST_CYGWIN=y``: Using Cygwin or other POSIX environment System Type -> Toolchain: * ``CONFIG_ARM_TOOLCHAIN_GNU_EABI=y``: General GCC EABI toolchain under windows This re-configuration should be done before making NuttX or else the subsequent 'make' will fail. If you have already attempted building NuttX then you will have to: 1. ``make distclean`` to remove the old configuration 2. ``tools/configure.sh sam3u-ek/ksnh`` to start with a fresh configuration, and 3. Perform the configuration changes above. Also, make sure that your PATH variable has the new path to your Atmel tools. Try ``which arm-none-eabi-gcc`` to make sure that you are selecting the right tool. See also the "NOTE about Windows native toolchains" in the section call "GNU Toolchain Options" above. nsh --- This configuration directory will built the NuttShell. The configuration configuration can be modified to include support for the on-board SRAM (1MB). System Type -> External Memory Configuration * ``CONFIG_SAM34_EXTSRAM0=y``: Select SRAM on CS0 * ``CONFIG_SAM34_EXTSRAM0SIZE=1048576``: Size=1MB Now what are you going to do with the SRAM. There are two choices: 1. To enable the NuttX RAM test that may be used to verify the external SRAM: System Type -> External Memory Configuration * ``CONFIG_SAM34_EXTSRAM0HEAP=n``: Don't add to heap Application Configuration -> System NSH Add-Ons * ``CONFIG_TESTING_RAMTEST=y``: Enable the RAM test built-in In this configuration, the SDRAM is not added to heap and so is not excessible to the applications. So the RAM test can be freely executed against the SRAM memory beginning at address ``0x6000:0000`` (CS0). .. code:: console nsh> ramtest -h Usage: [-w|h|b] Where: starting address of the test. number of memory locations (in bytes). -w Sets the width of a memory location to 32-bits. -h Sets the width of a memory location to 16-bits (default). -b Sets the width of a memory location to 8-bits. To test the entire external SRAM: .. code:: console nsh> ramtest 60000000 1048576 RAMTest: Marching ones: 60000000 1048576 RAMTest: Marching zeroes: 60000000 1048576 RAMTest: Pattern test: 60000000 1048576 55555555 aaaaaaaa RAMTest: Pattern test: 60000000 1048576 66666666 99999999 RAMTest: Pattern test: 60000000 1048576 33333333 cccccccc RAMTest: Address-in-address test: 60000000 1048576 2. To add this RAM to the NuttX heap, you would need to change the configuration as follows: System Type -> External Memory Configuration * ``CONFIG_SAM34_EXTSRAM0HEAP=y``: Add external RAM to heap Memory Management * ``-CONFIG_MM_REGIONS=1``: Only the internal SRAM * ``+CONFIG_MM_REGIONS=2``: Also include external SRAM